In battery materials, such as lead-acid batteries and lithium secondary batteries, development of electrode materials that have high capacities, accept a high current, and allow quick recharge has been attempted by way of making electrode materials into porous configurations and increasing the specific surface area so that active materials are effectively utilized and lithium is more rapidly diffused within electrodes.
For the electrically-conductive materials used for electrodes of secondary batteries, usage of electrically-conductive materials consisting primarily of silica and carbon has been already suggested. For example, Patent Document 1, to be explained below, discloses silica powder on which acetylene black is supported.
In the technique described in Patent Document 1, an expected type of acetylene black-supported silica is produced by: adding acetylene black in purified water so as to be suspended therein; adding and mixing silica powder in the suspension so that acetylene black is adsorbed on the surface of the silica powder; and evaporating the water.
Moreover, a method of obtaining composites of silicon dioxide and an electrically-conductive substance has been also considered, wherein tetramethoxysilane oligomer, phenolic resin, graphite particles, and so on are used as starting materials (see Patent Document 2).
In the technique described in Patent Document 2, expected composites are obtained as follows: tetramethoxysilane oligomer, phenolic resin, and methanol are mixed, and then graphite particles are added to the mixture; while distilling methanol, the mixture is heated to a predetermined temperature and maintained at the predetermined temperature for a predetermined duration so as to obtain a composite precursor; the composite precursor is subsequently heated up to 900° C., which makes phenolic resin and silane compound carbonized and decomposed; and the decomposition product is fired at 1300° C. for thermal reduction of silicon oxide with carbonized resin.